At the present, holding tanks and ponds for wastewaters contaminated with bacteria, fungi and viruses are treated with a variety of agents which are only slightly bacteriostatic, are not virucidal, and generally mask the odor of the holding tanks and ponds. Some of the additives used for holding tanks are: phenols, zinc sulfate, and formaldehydes. Data have not been forthcoming to indicate the above additives will sterilize holding tanks and ponds laden with organic waste. Chlorine is ineffective in the presence of such increased loads of organic compounds; these readily deplete the activity of chlorine by converting this oxidizing agent to chloramines. Formaldehyde is not effective at normal pH of wastewaters. In our copending application, Ser. No. 392,962, however, formaldehyde is enhanced and becomes quite effective to sterilize wastewaters.
Similarly, additives used in toilet bowls usually are scented, colored compounds which are only weakly bactericidal and not at all virucidal. The flushing of toilets results in aerosolization of a percentage of the infectious agents excreted therein, which may account for transmission of infectious diseases to the next person using the toilet, or even to the next person entering the washroom in which the toilet is located.
Since the passage of the 1972 Water Pollution Control Act, vessels are no longer allowed to discharge their wastewaters overboard, but must retain these wastewaters in holding tanks for eventual removal from the vessel after arrival in port. At this point the wastewater contaminated with bacteria and viruses is physically removed and then disposed of, often overloading land-based sewage disposal plants. Active microbiologic flora from wastewater from boats may eventually find their way to surface or ground waters.
The prevention of contamination of our surface and ground waters of viruses, bacteria and fungi is of signal importance to our ecologic problems as related to public health. Similarly, the prevention of aerosolization of a percentage of infectious agents excreted in toilets upon the flushing of the toilets is of signal importance in the prevention of transmission of infectious diseases to the next person using the toilet, or even to the next person entering the washroom in which the toilet is located.
It would be highly advantageous, and the present invention is directed to, a product and method which inactivate bacteria, fungi and viruses contained in organic wastewaters, clean waters, and hard surfaces, which make the storage of wastewaters in tanks, ponds and the like safe and practical, and reduce the aerosolization of infectious agents which often contaminate toilets.
It is also of importance that holdings tanks aboard sea-going vessels and submarines, and airplanes, as well as other land-based holding tanks, be maintained odor free by sterilization of the wastewater. Holding tanks which are not maintained sterile will contain increasing amounts of methane synthesized by bacterial activity, which presents a hazard. It would be highly advantageous, and the present invention is directed to a product and method by which such wastewaters may be sterilized by heretofore ineffective compounds, quaternary compounds, but unexpectedly these quaternary compounds sterilize these wastewaters inactivating bacteria and fungi when the wastewaters are brought to pH 9-11 or greater, and that compounds of the pyridinium group, e.g., cetyl pyridinium chloride (CPC) will inactivate viruses as well as bacteria and fungi when the wastewaters are brought to this basic pH of 9-11 or greater.
Although it is known in the literature that quaternary compounds are more efficient bactericidal agents at higher pH levels than at neutral pH, none of the products presently on the market which contain quaternary compounds (mostly cetyl pyridinium chloride) are at basic pH levels. In fact, most are in the acid range, e.g., Cepacol, Scope, etc.
Although it is documented that the quats are more active at basic pH levels, the levels which have been tested are at pH 8 to 9, and furthermore they have been tested in clean water systems without organic loads. We have shown that in the presence of heavy organic loads cetyl pyridinium chloride at neutral pH levels is completely ineffective as a disinfectant, whereas at pH 10 it is as effective in the presence of organics as it is in the absence of organics. Thus, in the present invention, the adjustment to basic pH levels renders the quaternary resistant to inactivation by organics; this has never been reported.